Wright d



(No Model.)

W. D. SMITH. DUST COLLECTOR.

No. 451,139. Patented Apr. 28, 1891.

m W I D45 mums PEYIIRS 00., Pun-ruuwm, WAskmarou, a. c.

25 preferably made of sheet metal.

NITED TATES \VRIGHT D. SMITH, OF DETROIT, MICHIGAN, ASSIGNOR TO THEHUYETT &

. SMITH MANUFACTURING COMPANY, OF SAME PLACE.

DUST-COLLECTOR.

SPECIFICATION forming part of Letters Patent No. 451,139, dated April28, 1891.

Application filed September 80, 1890. $eria1 No. 366,698. (No model.)

To all whom it may concern:

Be it known that I, WRIGHT D. SMITH, of the city of Detroit, in thecounty of \Vayne and State of Michigan, have invented new 5 and usefulImprovements in Dust-Collectors,

lo the interior of a chamber in such manner as to cause the depositionof the specificallyheavy particles by centrifugal action against thewall of the chamber down which they travel toward an orifice in thebottom, while I 5 the air freed from the solid particles escapes at thetop of the chamber,

In the drawings hereto attached and making a part of this specification,Figure 1 is a horizontal section through the air-induction pipe, andFig. 2 is a vertical central section of the entire machine.

The same letters are employed in both figures in the indication ofidentical parts.

The casing illustrated in the, drawings is The airblast is generated bya suction-fan or other form of blower in the usual manner, and itcarries on its current dust, shavings, or whatever analogous lightmaterial it may be de- 0 sired to move,which I will refer to hereinafterunder the general designation of dust. The separation takes place in aconical chamber, such as is in familiar use, and will be more fullydescribed hereinafter. This chamber is represented as arranged with itsaxis in vertical position, though this is not indispensable. The pipe Ais bent to form an elbow, the outer and inner walls of which aresegments of concentric circles, and extends until it abuts againstitself, and so forms what I shall call a return-elbow, although thisexpression is not intended to operate as a term of limitation to anelbow which actually terminates against the pipe; but the air isdelivered into the upper end of the separating-chamber through a slot B,which is cut in the bottom a of the pipe where it lies against the endof the chamber, and gradu ally increases in width from the beginningtothe end of the elbow, as clearly shown in Fig.

1. As the air is constrained by the pipe to take adirection conformingto its shape when it enters the elbow, it will be diverted into acircular path, and it will consequently develop a centrifugal actionupon the solid particles wafted by the current, so that they will tendto accumulate,but without actual separation in that portion of thecurrent which is contiguous to the exterior wall of the elbow, andconsequently the slot B should extend inwardly from that wall, so thatthe air and solid particles may find an unobstructed delivery from thepipe A into the separating chamber. This slot in the case as illustratedis in the wall a of the elbow which lies upon and forms part of the endof the chamber; but the elbow may obviously be separated from thechamber and the independent walls connected by a throat instead-of amere slot in the partition-wall. This arrangement of the slot alsopermits the air to be discharged downwardly into the separating chambernear its wall, and as the slot uniformly increases in width from theinduction end of the elbow, where it is quite narrow, to the stoppedend, where it may be expanded so as to extend entirely across the fullwidth of the elbow, and as the pressure of the air is great-est at theinduction end of the elbow and gradually diminishes toward the stoppedend, it follows that there will be an approximately uniform distributionof the dust-laden air around the Wall of the separating-chamber from thebeginning to the end of the slot or throat, because'the width of theslot increases as the pressure diminishes. The effective portion of thepipe in relation to the dust-collectors is that which is curved to formthe returnelbow. Anything beyond that is a more connection with thefan-case, and its length and position must be governed by extraneouscircumstances and the laws of pneumatics. The chamber 0 is preferably inthe form of an inverted truncated cone, such as is well known in thisclass of machines, and the separation takes place in the usual manner.The current of dust-laden air isintroduced as nearly as possible equallyaround the interior wall of the separating-chamber with a combineddownward and rotary movement, caus- IOO ing it to descend spirally,depositing the specifically-heavier particles on its interior face topass down to the small opening in the apex, while the air in the centerof the vortex formed by the rapidl -gyrating current escapes through thecomparatively-larger opening formed in the other end of the tube D,which in the case as illustrated is formed by the inner wall I) of thereturn-elbow, which closes on itself. This tube is cylindrical in form,being formed by the inner wall of the return-elbow, and is of the lengthof the entire depth of the air-induction pipe. It therefore affords anequal draft all around its circumference.

As it is sometimes desirable that a greater or less amount of air shallescape through the smaller end with the solid matter, provision is madefor regulating this by a damper acting to more or less open or close thearea of discharge through the large tube D. This may be done by anordinary damper-valve, such as is used in chimneys and other forms oftubes. I have shown, however, what I regard as a preferable form ofvalve for regulating this outflow. This consists of a cupformed disk E,carried on the end of a rod 0, which slides freely in eyes formed inbridge-trees d, placed across the tube D at or near its eX- tremities.This disk will be lifted by the escaping air-current and will fall onthe end of the tube D when the blast is stopped. Weights may be placedin the cup to load the valve moreor less to adapt it to air-currents ofvariant force. A set-screw e is tapped through a collar surrounding therod 0, by means of which the valve may be made fast, if desired, toestablish a fixed discharge of air through the tube D. This set-screwis, however, intended to be used only when for any reason it may bedesired to fix the disk in place. When the dust-collector is in usualoperation, it is intended that the disk shall be free to move up anddown with variations in the force of the air-blast.

I do not claim the disk, broadly, as a valve automatically shifting itsposition up or down, for I am aware that flap-valves have been used uponthe air-escape openings from dustcollectors, and also disks of metalfree to play up and down on stationary rods; but the former areobjectionable, because they necessarily cause an irregular airescape outof the opening, which is contracted on one side, and so will disturb theinterior air-current. The latter are liable to be lifted more on oneside than on the other, and therefore bind on the vertical rods whichguide its motion, and so do not play freely up and down.

The disk which I use for a valve is slightly conical in form with itsapex down, and is carried on a sliding rod held in two bearings at adistance from one another, and so the air escapes freely all around thedisk without any impediment whatever, and the rod, being guided by twobearings, can move only in a right line, and so is not liable to bind inits bearings, while its cup form permits the use of additional weightsbeing placed therein when the current is of unusual strength, when it isdesired to increase the resistance to the escape at the top, or when itis desired to increase the amount of air discharged with the'dustthrough the smaller hole at the bottom of the separating-chamber, as isnecessary when the shavings, &c., are discharged through a pipe carriedhorizontally.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In combination with a separating-chamber 0, having air and dustescape openings at opposite ends, an air-induction pipe formed with areturn-elbow A, and an opening B, of constantly-increasing width,leading from the elbow into the chamber, substantially as set forth.

2. In combination with a separa ing-chamber 0, having air and dustescape openings at its opposite ends, an air-induction pipe formed witha return-elbow A, theexternal and internal walls of which are defined byconcentric curves, and an opening B, of constantly-increasing Width,leading from the elbow into the chamber adj acently to the wall thereof,substantially as set forth.

3. In combination withtheseparating-chamber provided with adust-discharge opening atits lower end, a tubular upward air-dischargeand an automatically-adj ustable valve supported on a central movablerod guided by upper and lower bearings, substantially as set forth.

4:. Incombinationwiththe separating-chamber having a dust-dischargeopening at its lower end, a tubular upward air-discharge and acup-formed automatically-adjustable weighted valve supported on acentral movable rod guided by upper and lower bearings, substantially asset forth.

5. In combination with the induction-pipe formed with a return-elbow, adischarge-opening therefrom of constantly-increasing width, aseparating-chamber with a dust-discharge opening at its smaller end andan air-discharge at its larger end, and an adjustable valve regulatingthe relative amount of air discharged through the two openings,substantially as set forth.

In testimony whereof I have hereunto subscribed my name in the presenceof two attesting witnesses.

\V RIGHT D. SMITH.

Witnesses:

R. MAsoN, II. E. WHITAKER.

